1. Field of the Invention
The present invention relates to wireless sensor networks, and more particularly, to a communication method and apparatus using a virtual sink node in a wireless sensor network.
2. Description of the Related Art
In recent years, with the steady growth of Internet, wireless sensor network technology has been put to practical use in a variety of industrial fields. The development of low-priced sensors, the changing environment of international standards, etc., have all contributed to the advancement of this technology. In general, sensor networks detect information through sensors and process the detected information. Through the use of sensor networks, advancements have been achieved to improve everyday living and provide a variety of benefits in the application of science and technology. Sensor networks refer to a wireless network that serves to implement ubiquitous computing and includes a plurality of sensors that are light in weight and consume low power.
The conventional study of sensor networks has progressed without considering the issues created from the mobility of respective nodes in the sensor network. On the contrary, sensor networks have characteristics where each network includes a plurality of sensors, each of sensor nodes has restricted power and computing capability, and the topology of the sensor network can be easily changed because sensor nodes are inserted and removed into and from the network as the sensor nodes are frequently moved. Therefore, a study needs to be conducted that considers the mobility of respective nodes.
The conventional study of networks in an environment assuming node mobility has been with respect to a mobile ad-hoc network (MANET). However, studies on a routing method assuming the node mobility are only at the beginning stage. Examples of a routing protocol of the conventional MANET that provides support to nodes having mobility are: destination sequence distance vector (DSDV), ad-hoc on-demand distance vector (AODV), dynamic source routing (DSR), etc. These routing protocols use a method for periodically updating routing information through flooding, where each node includes a routing table to maintain a route between moving nodes, or a route searing technique of an on-demand method using flooding to detect a route of moving nodes.
However, since the route search of an on-demand method is performed, assuming a “many-to-many” communication environment but not assuming the restriction of devices, there has been a limitation of application to a sensor network that collects data in a sink node. That is, since the network performs frequent flooding to search a location of a sink node and thus increase its traffic, collision is increased and a large amount of energy is consumed. Therefore, the conventional sensor network, which must include limited resources according to the features of the devices, is difficult to apply to nodes.